I spoke to a concrete 'expert' about this.
I had never spoken about tufa to this fellow before and he had never heard of it.
His response to my peat theories.
"Are you nuts, why would anyone add organic material to concrete. Wet, dry, why waste your money, just use dirt, because it's just going to fall apart anyway"

I never bothered asking him about dusting the peat with a bit of lime.:)

Tufaenough,
By any chance did your experiment also include those bricks made with damp peat, having the bricks dry out then re-soaked for period of time/re-incorporating the water. How strong are they?
And how about the brick made with dry peat will they ever be able to soak up more water than you were able to get them to soak up before you got your mix into the brick mold?
:) :)
Dena

Maybe wet peat makes bigger lumps and weakens it this way, or maybe dry peat soaks up some of the portland along with the water and strengthens it in this manner. Tufaenough, you need to take your broken samples and look at them under magnification and see what the difference might be.

LOL!
I have a fine lab quality microscope but it's not the type you would use for that. Besides i have no idea what I would be looking for.

I no longer use damp peat in any of my recipes so someone else will have to solve the mystery of which makes stronger tufa and why.

Tufaenough, use a good magnifying glass or better yet a loop, and check out the peat particals in the broken end of the brick. Are they larger in the weaker brick? Smaller? Can you see any crystals in the peat in the stronger brick? I am the mad scientester and need to know these things. Since I did no test bricks and you did, you need to be the eyes. Iv'e got a good scope and have figured out "tufa under fire". You can see the crystal structure and it's break down. Give it a shot and let me know what you see.

Jo

I don't have much experience with Hypertufa (one small project), but for discussion, here is a theory:

Generally more water is in concrete than is needed for hydration of the cement in order to have workability (moldability, cohesiveness, compactability, etc.). Adding water beyond a certain point, results in weak concrete. Although some mixing water is absorbed initially by the dry peat in hypertufa, the peat may still have additional capability to absorb additional moisture from the mix and release it slowly to aid in hydrating the cement in the interior portions of the piece as it cures.

Hi John
You might have something there.
That might explain why vermiculite seems to make stronger concrete than Perlite.
It absorbs water then releases back into the concrete.
Perlite doesn't absorb anywhere near as much water.

Lurker here. (Everyone does it on at least one forum.) Let me expound on some things already mentioned:

Peat has an incredible amount of surface area. When dry peat is used, and as it absorbs water, my theory is that it pulls cement particles into the miniscule natural crevices and so the cement becomes "part of the peat fiber". So the fiber is tronger.

If you sift dry peat, there will be no clumping because dry ingredients are mixed together first. Of course, you can't sift moist peat, but moistened dry-sifted peat could clump, and prevent a homogenious mixture. In addition, there would be no "pulling in" effect by the peat on the cement because it is already moist.

When we make troughs, the finished mix sets for 15-20 minutes before we work with it. Hopefully we added enough water, but if the peat absorbs too much of the moisture, we make a final adjustment after that period. I'm not saying it's the best of worlds here, but it works for us. Misting? Never done it.

My first outdoor trough is 21 years old here in Minnesota. It is still in good condition.

Hi Rick
That makes perfect sense to me.
There is no doubt in my mind at least in the short term (several months) that dry peat makes much stronger Tufa than damp peat.
And let me say WOW to your 21 year old trough.
I would love to see a picture of that puppy.

leftwood, Welcome lurker!
I took a class a few years ago from Joyce Fingerut and bought her and Murfitt's book, "Creating and Planting Garden Trough".
What are you growing in your old trough? I grow mostly trees and shrubs in mine year round. Use small sedums as fillers in my mini landscapes. Billie

Pics of my 21 year old. You wouldn't think it by looking at it , but it is made with a 1:1.5:1.5 recipe of portland, peat and vermiculite.
{{gwi:72025}}
{{gwi:72026}}

Growing in the trough now is a plain Sempervivum that bloom itself out this year, Escobaria viviparia, an aged Dunce caps that's just about ready to give up, Sedum acre, Delosperma nubigeum(almost lost it to mold this winter) and a variegated Sedum acre. This one is pretty unspectacular. But Billie, if you'd like to see more of mine and others', click here.

Rick

I should also add that come winter, and although it freezes and thaws without any precipitation covering until the ground freezes permanently to a depth of at least 3 inches, there after it is covered for the rest of the winter. Reinforcement in this one is chicken wire.

Rick

Rick, Here's a 12 year (left) & 6 year (right) planter. I'm not into alpine or bonsai, just like mini landscapes. I move them into larger planters when they can't stand being root pruned and pinched. In my zone I leave these out all Winter, no mulch just on the deck or in garden beds. If there's a thaw and no snow I water them. If there's snow I make sure to pack it on the planters. This was portland cement, sand and peat moss. You can see how the peat moss disolves over time. Billie

Here is a link that might be useful: {{gwi:72023}}

Hi Rick
It's interesting that the surviors are actually bowls.
very nice look btw.
I have found a few older bowls in my area as well.
But the rectangular shapes, that I think of as troughs are a different kettle of fish.
All my purchased concrete winter survivors are round as well.
Bowls are a probably a good choice for bad freeze thaw areas. Strong with minimal ground contact. I have even tested mine in my freezer and they do not break.

Rick, I don't have to put little bricks in a freezer to see what will stand up to the weather. Disregard the newbie, he posts on everything and doesn't have anything more than 6 months old. Billie

Here is a link that might be useful: {{gwi:72024}}

Jealosy?:)
Zone4 and z3 weather is much much harder on concrete than z6.

I know a fair bit about concrete. I have hand poured tons of the stuff over fifteen years.
This concrete and rock waterfall has survived over a decade in a Z5 with no cracks. There are two bowls in ground you cannot see. One is 3 feet by 16 inches deep and the top one is 3 feet by 10 inches deep.
The one with the fish at the bottom is over 3 feet deep and almost 8 feet across. It is completely covered with embeded rocks like you see around the edge except for the very bottom of the bowl. Only a few have popped out from ice damage.
All those rocks some weighing hundreds of ponds are set in hand finshed colored concrete. this is completely covered and filled with snow and ice every year.
{{gwi:72027}}

And I've made at least 1000 pounds of tufa and concrete projects this year. I doubt some people have done that much in the last 20 years.

Regarding the bowls vs. trough winter survival skills debate: Joyce Fingerhut and Rex Murfitt published a book Creating & Planting Garden Troughs. There it is mentioned that straight-sided troughs shouldn't be allowed to fill up with snow and ice because the expansion against the walls may cause the walls to break/crack. Bowls and slant sided troughs don't have this problem because the ice is able to slide up the sides because of the angle and is pushed out the top. When I make my troughs, I try to give the interior walls a little slant so that the expansion will push up and out and not sideways against the walls.

Maybe this will help. Not looking for any additional trouble, I just turn my troughs over in the winter and haven't had one break yet.

Thanks Club 53
I also read that, but I hate to tell folks in cold areas that large troughs are not possible. I think with proper ground prep and a few precautions square troughs are doable and can survive.

I just wish some here would stop misleading newbies about this.
I'm just about the only one who warns those planning to make large on ground troughs about the dangers of freeze thaws and how to possibly protect against it.
I have received several emails from long time lurkers wishing I was around in previous years.
They followed bad advice given here and when their troughs broke they were told they made them wrong, used bad cement, etc.
One lady in a Z4 lost 4 huge troughs she spent the whole summer making following the advice given, word for word, by a regular here, only to be told she didn't know what she was doing and to try again. She was never warned about how to protect her work from freeze thaw.
After they broke she was told that she should have turned her troughs over for winter. They were over 200 pounds each.
If she had placed them on a bed of drain rock and covered them with clear 6 mil poly I believe both the toughs and her plants would have done just fine.
But as I'm a newbie to tufa I can't give advice based on personal experience, and thus far I haven't found anyone with large on ground troughs that have survived z3 and z4 winters. Not even z5 winters.

Good points about square vs. round and vertical vs. slanted sides. Notice my old round one has low, sloping sides too. My peat is always sifted before incorporation, so I don't get voids in aged troughs that some do.

I really don't have any old square ones: only about 5 years aged. I'll just have to see. People up here are going heavily into styrofoam troughs too. Some say they have better winter survival of plant materials in these.

Nice artwork on those troughs, Billie_ann.

Rick

P.S. I think I've been lurking long enough to know who knows their stuff here.

Rick
"P.S. I think I've been lurking long enough to know who knows their stuff here."

Thanks Rick!:)

Deb, I'll have to re-read "Creating & Planting Garden Troughs" about the straight sided troughs. Don't remember reading that. Most of mine are planted with trees, shrubs and perennials and can leave them outside all Winter. If a planter is empty I store it just as they recommend for concrete planters, upside down or in a shed for the Winter.
Rick, thanks for the compliment. I do like the decorated troughs and planters but not for everything. You don't want the planter to be the center of attention but some accents are nice. Joyce called my stuff the "artistic" form when I took her class. Billie

Rick:

I've been hearing a lot lately about those styrofoam troughs. Has anybody seen one in use yet? A web site about them says that they are kind of easy to break -- it warns about pulling them by the side because the side will break and also to make sure that two people are used to move them to prevent breakage. Any idea how they hold up? They sound good in theory, but wonder just how durable they really are. Could be interesting in the house tho.

Hi Tufa Enough:

By the way, your waterfall is fab. I am not sure if we all have different definitions of what "large" is. Is it possible that we sometimes forget that our troughs are not stone, and no matter if they are made of hypertufa or straight concrete, we have to remember to reasonably protect them from the anticipated harsh cold, ice, rain, sleet & snow and other Northern deights. I had a sale this weekend, and someone was asking and asking and asking about durability (like the things were supposed to withstand a nuclear blast for heaven's sake) -- I told her that like anything we own, they require reasonable care -- and that if she, for example, left these things out in a puddle of water and there was a lot of freezing and thawing they were probably going to break -- wonder what the weather was on her planet?

Thanks Club

When I say large trough I mean one that cannot feasibly be turned over or emptied for winter. In my area such a trough sitting on dirt will be torn apart by ice and frost heaves.
I believe proper ground prep, which in our area this includes several inches of drain rock can protect against the ice from below. A simple tent made from inexpensive 6 mil poly should help protect from above.
Other considerations are soils that shrink away for the sides, possibly making the troughs bottomless. Make the walls with a lip for a styrofoam bottom.
There are many ideas and possible solutions to be discussed but you can't discuss them here without being attacked.
So those looking to build large troughs in cold areas won't find much help here I'm afraid.

About the styrofoam troughs, I'll put my click here link again. The first trough is styrofoam.

You do need to use strong styrofoam, like those used for fish at fish markets and grocery stores. And yes, it would break if you pulled it by the side. (Geeze, what do you think they're made out of? Hypertufa?) Just try draging any styro box with 20+ pounds of load in it. Of course it will break! But really, they are stronger than you'd think. I pick up the one pictured(24x15") myself, without any aid. No board underneath is needed, although I do try to be extra safe and use one anyway. And it's only common sense that you would try to get your hands under the box rather than holding it by the edges.

Rick

Rick, well, duhh, of course they aren't as strong -- it just seems from reading a site making troughs out of styrofoam fish boxes, that there are a lot of instructions and rules about not sliding, using two people to lift them -- always -- etc. Just figured that if I had to fuss that much, I would use something more durable in the first place -- like hypertufa -- and maybe line it with styrofoam if insulation was needed.

Spoke with a family member who's an engineer with lots of "sperience" with concrete. Here's what he said.

Concrete is something that of which I know. More water does mean less strength, but poor workability leads to incomplete consolidation, air pockets, sand pockets, and other stuff that is worse than the slight loss of strength caused by a little extra water.

The peat moss is a special case. Since peat has no inherent strength, it needs to be saturated with the cement paste. If the peat particles are already saturated with water before the cement is added, you'll get less cement saturation of the peat.

So, don't add the water to the peat and then throw in the cement. Better to make a cement mix a little too wet and then throw in the dry or slightly damp peat. The peat will suck up some cement paste. This is a good thing. Even though it stiffens the mix somewhat, you can readjust the workability with a little more water or a little more dry cement if you get too heavy handed with the water.

Deb, I think those "rules" about styrofoam troughs are for the idiots. Like when it says on a plastic bag: "Do not place head inside bag." You know, they're for people who just don't get it. You're not an idiot, Deb. Just use your horse sense.

Rick: Thanks for the leap of faith that I'm not an idiot :) I plan on making some troughs to sell that have a lion's face on them for that European antiquities look, and had to figure a way to incorporate the face mold to be part of the form in order to make the finished product "idiot proof" -- afraid that if I attach the face to the finished trough with Liquid Nail or the like, some moron is going to figure out a way to knock it off -- and you just know it is going to be the world's biggest PIA who manages it!!!

Thanks for the update on surviving the frosts. I tested a cylinder pot that I make in the freezer: Fill it with soil and water, and freeze/thaw 4 times. It cracked in two. The plug of ice was just too much for the 'tufa. My advice for the people I talk to is still : if you can, protect it and bring it in, if you can't, get it off the ground to keep it dry. I was thinking about no more straight sides, but there's hope.

Been a crazy summer. How's yours been?

Blooming